The fertility doctor who helped a California woman have 14 children, including octuplets born last month, is now facing a state investigation on top of harsh criticism from medical ethicists.

The fertility doctor who helped a California woman have 14 children, including octuplets born last month, is now facing a state investigation on top of harsh criticism from medical ethicists.

The Medical Board of California did not identify the doctor who helped Nadya Suleman, 33, of Whittier, become pregnant with the six boys and two girls born on January 26, even though she already had six other children.

"We're looking into the matter to see if we can substantiate if there was a violation of the standard of care," board spokeswoman Candis Cohen said Friday.

Suleman, a divorced single mother, told NBC's Today show that the same fertility specialist provided in vitro fertilisation for all 14 children.

In the interview broadcast on Friday, Suleman also said six embryos were implanted for each of her pregnancies. In her latest, two of Suleman's embryos split, resulting in two sets of twins among the octuplets.

When asked why so many embryos were implanted, Suleman said, "Those are my children, and that's what was available and I used them. So, I took a risk. It's a gamble. It always is." Doctors say the norm is to implant two or three embryos, at most, in women Suleman's age.

"The revelation about one center treating her makes the treatment even harder to understand," said Arthur Caplan, bioethics chairman at the University of Pennsylvania. "They went ahead when she had six kids, knowing that she was a single mom ... and put embryos into her anyway."

Suleman's infants were born prematurely and are expected to remain in the hospital for several more weeks. Her six other children are between ages 2 and 7.

Suleman said she had never been on welfare and would find a way to get by with the help of family, friends and her church. She said she planned to return to school in the fall.

"All I wanted was children. I wanted to be a mom. That's all I ever wanted in my life," Suleman said in the portion of the interview that aired on Friday. "I love my children." She said she struggled for seven years before finally giving birth to her first child.

According to state documents, Suleman told a doctor she had three miscarriages. Another doctor disputed that number, saying she had two ectopic pregnancies, a dangerous condition in which a fertilized egg implants somewhere other than in the uterus.

The state documents describe Suleman becoming pregnant with her first child after a 1999 injury during a riot at a state mental hospital where she worked. Suleman feared she would lose the child and sunk into an intense depression, according to a psychological evaluation in her workers' compensation case.

"When you have a history of miscarriages, you think it will take a miracle," she told Dr. Dennis Nehamen. "I just wanted to die. I suspected I was pregnant but I thought, 'That's ridiculous."' But the 2001 birth of the baby "helped my spirits," Suleman said.

More than 300 pages of documents were disclosed to The Associated Press following a public records request to the state Division of Workers' Compensation. Among other things, they reveal that Suleman collected more than $165,000 in disability payments between 2002 and 2008 for the work injury, which she said left her in near-constant pain and helped end her marriage.